Method for air quenching an elongated glass hollow body comprising an axial bore

ABSTRACT

An installation for quenching a glass hollow body includes a plurality of external nozzles and an axial nozzle. The plurality of external nozzles are positioned around a main axis. Each of the plurality of external nozzles includes an axial slot configured to direct an air jet towards the main axis. The axial nozzle is aligned along the main axis and includes a shape configured to form an internal air jet forming a ring with an opening at a center thereof in a plane transverse to the main axis. The axial nozzle forming the internal air jet positioned substantially external to and above the bore.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional application of U.S. NationalPhase Application Number 16/461,117, filed May 15, 2019, which claimspriority to and the benefit of International Application No.PCT/FR2017/053036, filed on Nov. 7, 2017, which claims priority to andthe benefit of FR 16/61064, filed on Nov. 15, 2016. The disclosures ofthe above applications are incorporated herein by reference.

FIELD

The present disclosure relates to a method for air quenching a glasshollow body, as well as a quenching installation implementing such aquenching method, and a device for injection under the skin containingsuch a hollow body.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

One type of known injection device, presented in particular by thedocument FR-A1-2815544, is provided for carrying out intradermal,subcutaneous or intramuscular needleless injections of activeingredients contained in a fluid for therapeutic use in human medicineor veterinary medicine. The fluid may be a gel or a more or less viscousliquid.

These single-use devices contain a source of energy such as apressurized gas generator, delivering a gas suddenly released on aplunger fitted into a cylinder formed by a glass tube, to propel thefluid contained below this plunger towards an injection nozzle incontact with the skin, and inject it under this skin.

The glass tube must have accurate dimensions in order to achieve sealingat the ends, and around the plunger sliding therein. In addition, thistube must have a high mechanical strength to withstand the shock comingfrom the sudden pressure established inside by the pressurized gas.

To obtain a high mechanical strength of a glass tube having a main axis,a known air quenching method, presented in particular by the documentUS-A1-20060016220, uses a quenching installation carrying out a coolingby air blasting, including eight columns distributed around the tubeparallel to this tube, each comprising a series of discrete nozzlesextending over the height of this tube, and directed radially towardsthe axis, and an axial nozzle coming above the bore of the tube.

After having heated the tube to a required temperature, all nozzles aresuddenly supplied with pressurized air to cool at the same time theoutside by the radial nozzles, and the inside by the axial jet comingfrom above the bore of the tube.

A sudden cooling forming a quenching of the surface layers of the twosurfaces of the wall of the tube, inside and outside this tube, and aslower cooling of the material between the two skin layers of this tubeare obtained. Then there is a pressure prestressing on the skin layers,and a prestressing tension in the inside material between these layers,which confers a high strength to the tube thus treated.

Nonetheless, this method results in uneven distribution of the coolingrate on the internal surfaces of the wall of the tube, which confers tothis tube a variable strength along the height of the bore.

SUMMARY

In one form of the present disclosure, a method for air quenching aglass hollow body elongated along a main axis is provided, including awall having an external surface, and an internal surface formed by abore extending in a height direction along the main axis, this methodusing air blast nozzles directed towards the surfaces, being remarkablein that it simultaneously blasts air jets by external nozzlesdistributed over the external surface, and above the bore in the axis aninternal air jet forming in a transverse plane a crown having a recessat the center. For example, in some aspects of the present disclosure,the method comprises simultaneously blasting and distributing air jetsover the external surface and the internal surface of the glass hollowbody. An an internal air jet is distributed over the internal surface,aligned along the main axis and in a transverse plane to the main axisis in the form of a crown with a recess at the center.

An advantage of this quenching method is that in addition to the airjets over the entirety of the external surface, the blast inside thebore of the hollow air jet disposed along the axis, directly directs theair of this jet on the internal walls to cool them as quickly aspossible, without unnecessary loss of air flow rate in the center thatwould cross the bore by emerging from the other side withoutcontributing to cool the walls.

A better evacuation of the hot air, and with the same flow rate, amaximum efficiency on the inner wall of the tube, are obtained giving amore uniform cooling over the entire height of the glass hollow body.

In addition, the quenching method according to the present disclosuremay include one or more of the following features, which may be combinedwith each other.

Advantageously, the quenching method blasts air through an axial nozzleopening above the bore.

In this case, advantageously the method blasts air through an axialnozzle comprising a shape that opens forming a crown.

Advantageously, the method blasts air through external nozzles having anaxial slot. A better distribution of fresh air can also be obtained overthe external and internal surfaces.

Advantageously, all the external nozzles have an axial slot whichextends substantially over the entire height of the external surface tobe treated.

Advantageously, during quenching, the method rotates the air jetrelative to the hollow body about the main axis. The cooling on thecontour of the internal and external surfaces is regulated.

In another form of the present disclosure, an installation for quenchinga glass hollow body includes nozzles for blasting air on this body.Particularly, a plurality of external nozzles are positioned around amain axis of the installation and each of the plurality of externalnozzles comprise an axial slot configured to direct an air jet towardsthe main axis. In some aspects of the present disclosure, the pluralityof external nozzles rotate about the main axis during blasting of airjets directed to the main axis. An axial nozzle is aligned along themain axis and comprises a shape configured to form an internal air jet ashape in a transverse plane to the main axis of a crown with a recess ata center of the crown.

Advantageously, the installation includes an axial nozzle having a shapewhich opens comprising an axial core connected by radii to an externalcontour.

In some aspects of the present disclosure, the method and theinstallation provide a reservoir for containing fluid. In such aspects,the reservoir is part of a needleless injection device for carrying outintradermal, subcutaneous or intramuscular injections of activeingredients contained in a fluid for therapeutic use. The reservoir isformed from a glass tube constituting a hollow body made using themethod and installation according to the teachings of the presentdisclosure.

In some aspects of the present disclosure, the reservoir may contain afluid having at least one active ingredient selected from the groupcomprising the following treatment active ingredients:

-   Methotrexate,-   Adrenaline,-   Sumatriptan,-   Hydrocortisone,-   Naloxone,-   Midazolam,-   Apomorphine,-   Methylnaltrexone bromide,-   Phytomenadione,-   Chlorpromazine hydrochloride,-   Zuclopenthixol acetate,-   Danaparoid sodium,-   Enoxaparin sodium,-   Estradiol cypionate,-   Medroxyprogesterone acetate,-   Medroparine calcium,-   Methylprednisolone acetate,-   Heparin calcium, and-   Terbutaline.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

DRAWINGS

In order that the disclosure may be well understood, there will now bedescribed various forms thereof, given by way of example, referencebeing made to the accompanying drawings, in which:

FIG. 1 is an axial sectional view of an installation for quenching aglass tube, implementing a quenching method according to the teachingsof the present disclosure;

FIG. 2 is a cross-sectional view along the section plane II-II of an airblasting external cylinder of this installation;

FIG. 3 is a graph showing residual stress measurements in the wall ofthis glass tube, with a quenching method according to the prior art;

FIG. 4 is a similar graph as shown in FIG. 3 for a quenching methodaccording to the teachings of the present disclosure;

FIG. 5 is a graph showing cooling curves of a glass tube for the twoquenching methods shown hereinabove; and

FIG. 6 shows a front view of an axial nozzle of a quenching installationaccording to the teachings of the present disclosure; and

FIG. 7 shows a cross-sectional view along the section plane VII-VII forthe axial nozzle in FIG. 6 .

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses. Itshould be understood that throughout the drawings, correspondingreference numerals indicate like or corresponding parts and features.

FIG. 1 shows a glass tube 2 (also referred to herein simply as a “tube”)of revolution about an axis shown vertically, including a tubularcylindrical portion 8 comprising a wall of constant thickness E,terminating at the bottom in a lower bead 4, and at the top in an upperbead 6 having a more height (vertical direction in the figures) than thelower bead 4.

In FIG. 1 an axis (dotted line) is shown vertically with the upperportion of the tube 2 being conventionally called the top, however thetube 2 may lie in any orientation during a quenching method according tothe teachings of the present disclosure.

The tube 2 has an axial bore comprising a constant circular sectionalong the entire height, leaving on the cylindrical portion 8 a wallincluding a relatively important thickness E of several millimeters,which in some aspects of the present disclosure is substantially equalto the radius of the bore.

The lower bead 4 and upper bead 6 confer significant rigidity to theends of the tube 2, and form planar transverse end surfaces receiving aseal. In some aspects of the present disclosure, the tube 2 has a totalheight of about 30 mm, however tube with a total height less than 30 mmor greater than 30 mm are included within the teachings of the presentdisclosure.

The glass tube 2 is part of an injection device presented in particularby the above-mentioned document of the prior art, receiving in its axialbore a plunger subjected on the upper side to a sudden discharge of apressurized gas, in order to inject under the skin a fluid located inthe lower portion.

The sudden shock of the gas pressure pressurizes the fluid. The wall ofthe cylindrical portion 8 of the tube 2 must withstand the pressureshock coming from the gas and transmitted to the fluid.

FIG. 3 represents, for a quenching method shown in particular by theabove-mentioned document of the prior art, as a function of the positionin the thickness of the wall of the cylindrical portion 8 of the tube 2,represented by the radius relative to the axis of this tube expressed inmillimeters, a measurement of the residual stress in this wall performedby photoelasticimetry at different heights of this cylindrical portion.

The residual stress expressed in MPa, includes a first curve 30 ofmeasurements performed on the upper 5 mm of the cylindrical portion 8 ofthe tube 2, a second curve 32 of measurements performed on the median 5mm, and a third curve 34 of measurements performed on the lower 5 mm ofthis cylindrical portion.

Photoelasticimetry allows visualizing the existing stresses in thematerial inside the walls thanks to their photoelasticity, by using therefringence of an optical radiation crossing this material subjected tostresses. The polarization of the transformed light is studied afterpassing throughout the material.

For the three curves 30, 32, 34 measured on the cylindrical portion 8 atthree different heights, the application of compressive stressescorresponding to negative stresses for thicknesses starting from theinternal 12 and external 10 surfaces, which are in the range of ⅕ of thethickness E of the wall of the tube, is observed.

Nonetheless, it is noticed that the negative stresses applied on theinner wall of the tube have a high inequality along the height in thetube 2, which results in a highly variable strength of this tube.

Referring back to FIGS. 1 and 2 , around the tube 2 a series of externalcylinders 20 are disposed parallel to this tube, regularly distributedaround this tube, each having an external nozzle 22 turned towards theaxis, forming a continuous slot disposed opposite the height to betreated of this tube.

An axial nozzle 28 disposed along the axis above the bore of the tube 2,delivers in this bore an air flow rate forming in a transverse plane acrown, having at the center a recess 68 where the flow rate is absent.

The external cylinders 20 as well as the axial nozzle 28 are supplied atthe upper end by a considerable fresh air flow rate.

The installation includes a motorization of the external cylinders 20,which drives these cylinders and therefore the jets of air blasted inrapid rotation along the axis during the air quenching.

In this way, both a good axial distribution of the air flow to theoutside through the continuous slots of the external nozzles 22, as wellas a good angular distribution through the rotation of the cylinders 20allowing the flow of air in an equivalent manner over the entire contourof the external surface 10 are obtained.

An improved air flow rate inside the bore is also obtained, the air jetwith the internal recess 68 forming a crown which concentrates this airon the internal surface 12. With an equivalent air flow rate, it ispossible to obtain better cooling of this internal surface 12 over theentire height.

FIG. 4 shows for the quenching method according to the presentdisclosure, as a function of the thickness E of the wall of thecylindrical portion 8 of the tube 2, the residual stress inside thiswall.

There are a first curve 40 of measurements performed on the upper 5 mmof the cylindrical portion 8 of the tube 2, a second curve 42 ofmeasurements performed on the 5 mm of the median transverse plane, and athird curve 44 of measurements performed on the lower 5 mm of thiscylindrical portion.

For the three curves 40, 42, 44 measured on the cylindrical portion 8 atthree different heights, the application of compressive stressescorresponding to negative stresses, on thicknesses starting from theinternal 12 and external 10 surfaces, are in the range of ⅕ of thethickness E of the wall of the tube, is also observed.

Nonetheless, it can be observed that the negative stresses applied onthe inner wall of the tube have a good equality along the height in thetube 2, which confers a very constant strength to this tube.

Hence, a high homogeneity of the strength of the entire tube 2, which isclose to the maximum strength obtained with the method according to theprior art, is obtained.

FIG. 5 shows as a function of time T expressed in seconds on thehorizontal axis, the maximum temperature measured on the tube during thecooling phase, expressed in °C.

Two first curves 50 represent the maximum temperature for a methodaccording to the prior art shown hereinabove, and two second curves 52represent the temperature for a method according to the presentdisclosure.

For all the curves 50, 52, an equivalent decrease of the temperature isobserved up to the time equal to 2.5 s, with a temperature reached ofabout 480° C. Then a faster decrease of the temperature is observed forthe two second curves 52, which reaches after 6 s a temperature littlelower than 300° C., while the temperature of the first curves 50 isstill at 400° C.

With the following method according to the present disclosure, a fastertemperature drop is obtained, as well as a better distribution of thistemperature drop, which confers the best strength qualities to the tube2.

FIGS. 6 and 7 show an axial nozzle 28 comprising an inlet IN and anoutlet S, including in the lower portion an external tapping 62 providedto screw a support, the upper head 60 forming an impression to provide akey 61 for clamping on this support.

The lower portion of the axial nozzle 28 includes a shape openingdownwards, comprising an axial core connected by three radii 66 of smallthickness to the external contour. In this way, three air passagesforming circular arcs 64 are disposed, which deliver the air jetconstituting a crown comprising the central recess 68.

With the method according to the present disclosure, it is possible tocarry out an air quenching on an elongated hollow body having differentshapes, comprising an axial bore.

The method is particularly suitable for a tube of a device for injectionunder the skin, forming a reservoir containing a fluid including atleast one active ingredient selected from the group comprising thefollowing treatment active ingredients:

-   Methotrexate,-   Adrenaline,-   Sumatriptan,-   Hydrocortisone,-   Naloxone,-   Midazolam,-   Apomorphine,-   Methylnaltrexone bromide,-   Phytomenadione,-   Chlorpromazine hydrochloride,-   Zuclopenthixol acetate,-   Danaparoid sodium,-   Enoxaparin sodium,-   Estradiol cypionate,-   Medroxyprogesterone acetate,-   Medroparine calcium,-   Methylprednisolone acetate,-   Heparin calcium,-   Terbutaline.

Unless otherwise expressly indicated herein, all numerical valuesindicating mechanical/thermal properties, compositional percentages,dimensions and/or tolerances, or other characteristics are to beunderstood as modified by the word “about” or “approximately” indescribing the scope of the present disclosure. This modification isdesired for various reasons including industrial practice, manufacturingtechnology, and testing capability.

As used herein, the phrase at least one of A, B, and C should beconstrued to mean a logical (A OR B OR C), using a non-exclusive logicalOR, and should not be construed to mean “at least one of A, at least oneof B, and at least one of C.”

The description of the disclosure is merely exemplary in nature and,thus, variations that do not depart from the substance of the disclosureare intended to be within the scope of the disclosure. Such variationsare not to be regarded as a departure from the spirit and scope of thedisclosure.

What is claimed is:
 1. An installation for quenching a glass hollowbody, the quenching installation comprising: a plurality of externalnozzles positioned around a main axis, wherein each of the plurality ofexternal nozzles comprise an axial slot configured to direct an air jettowards the main axis; and an axial nozzle aligned along the main axisand comprising a shape configured to form an internal air jet forming aring with an opening at a center thereof in a plane transverse to themain axis, wherein the axial nozzle forming the internal air jet ispositioned substantially external to and above a bore extending alongthe main axis.
 2. The installation according to claim 1, wherein theshape comprises an axial core connected by radii to an external contour.3. The installation according to claim 1, wherein the axial slot extendssubstantially over an entire height of an external surface of a glasshollow tube positioned and aligned along the main axis.
 4. Theinstallation according to claim 1, wherein the plurality of externalnozzles rotate about the main axis during blasting of air jets directedto the main axis.
 5. A needleless injection device carrying outintradermal, subcutaneous or intramuscular injections of activeingredients contained in a fluid for therapeutic use, wherein theneedleless injection device includes a reservoir containing the fluidand defined by a glass tube constituting a hollow body made bysimultaneously blasting and distributing air jets over an externalsurface and an internal surface of the glass hollow body, wherein aninternal air jet distributed over the internal surface is aligned alonga main axis of the glass hollow body, wherein an axial nozzle blastingthe internal air jet is positioned substantially external to and above abore extending along the main axis, wherein a portion of the axialnozzle includes a solid axial core and an external wall cooperating witheach other to define circular arc shaped passages therebetween, theinternal air jet flowing through the circular arc shaped passages formsa ring with an opening at a center thereof in a plane transverse to themain axis.
 6. The needleless injection device according to claim 5,wherein the reservoir contains a fluid having at least one activeingredient selected from a group comprising the following treatmentactive ingredients: Methotrexate, Adrenaline, Sumatriptan,Hydrocortisone, Naloxone, Midazolam, Apomorphine, Methylnaltrexonebromide, Phytomenadione, Chlorpromazine hydrochloride, Zuclopenthixolacetate, Danaparoid sodium, Enoxaparin sodium, Estradiol cypionate,Medroxyprogesterone acetate, Medroparine calcium, Methylprednisoloneacetate, Heparin calcium, Terbutaline.